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Svenska
February 22nd, 2016, 04:16 PM
Hi,

I have received a Bondwell B310 laptop some time ago, a friend's attic-find. The machine is essentially a standard AT (80286-12, 1 MB RAM, CGA, 1.44 MB floppy, 40 MB hard drive).

The machine suffered from spurious resets. Although all electrolytic capacitors looked fine, I have replaced most of them. I have yet to see if that solved the problems. The original hard drive was extremely slow, and I suspected it to be dying (probably due to the constant resets); I replaced it with a (much faster) old 20 MB Conner drive I had lying around. However, it seems to be dying now too. I can't connect other drives, since the power connector does not fit. Not sure what to make of it yet, maybe I'll try a CompactFlash adapter. Those might work without a power connection...

Another issue is the LCD backlight. Sometimes, it is very bright and a relatively loud noise (very high frequency beeping, for lack of a better word) can be heard. Sometimes, the backlight is quite dim (but definitely active), and the beeping is quieter. Does someone have any idea what might be the cause?

The memory itself is built from 8 chips (256Kx4) and can be extended to 2 MB total, probably with another set of 8 256Kx4 chips, which I have available. Two 18-pin connectors (J5 and J6) are used for that, but I don't know the pinout. So far, I have traced out 16 data lines, 9 address lines, /WE, three GND and two VCC pins. Does someone know the pinout of that connector, or could post a picture of one?

PS: The AWARD BIOS boots fine without the CMOS battery attached. Strangely, the settings default to EGA, which of course does not work.

Best Regards,
Svenska

Krille
February 22nd, 2016, 11:47 PM
The resets could be the result from loss of the POWER_GOOD signal which indicates a problem with the PSU. But I'm sure you knew that already.

Svenska
February 24th, 2016, 03:32 PM
That laptop does not contain a PSU, it uses a 9V DC barrel connector or the battery (which I don't have) for power.
ATX is almost a decade younger than this laptop.

Krille
February 25th, 2016, 04:46 AM
Ah yes, sorry. I guess my brain didn't fully register that this is a laptop we're talking about. Anyway, all the issues you described sound to me like some kind of power distribution problem but I'm definitely not an EE so I should probably just shut the hell up and let someone else do the talking. ;)

BTW, POWER_GOOD was from the AT standard. It's called POWER_OK in ATX.

Svenska
February 25th, 2016, 04:28 PM
Sorry for being a bit harsh. I didn't know that AT did have a POWER_GOOD signal, so I learned something new as well. :-)

I wonder if someone else knows more. Especially a photo of the original memory expansion (or a schematic) would be awesome.